Many types of systems include a rotating shaft. For example, electric motors and internal combustion engines drive shafts and/or transmissions of vehicles, crafts, manufacturing systems, and other devices. While a rotating shaft may be exposed to normally occurring resistive loads, cyclic and intermittent forces may be fed back into the shafts and transmissions from other components and loads. Combined with the normally occurring forces, such additional forces may reduce the service life of the rotating shaft. Further, such abnormal forces and vibrations may result in a failure of the shaft that may damage other components as well.